Tailoring a variety of materials has been described in U.S. Pat. Nos. 6,572,792 and 7,238,297, entitled “COMPOSITION OF MATTER TAILORING: SYSTEM I” and U.S. Ser. No. 11/063,694 entitled “COMPOSITION OF MATTER TAILORING: SYSTEM II”, filed Feb. 23, 2005, each by Christopher Nagel, the contents of which are incorporated herein by reference. In the methods described in the prior patents, carbon is added to the material in an iterative heating cycle and the products produced by the methods possess modified electronic structures. Improvements in process control are desirable.